The Convergence of Vasculopathy and Vasculitis: Computer Mapping Analysis of 2 Renal Biopsies in a Patient with both Systemic Sclerosis and ANCA-Related Vasculitis

Scleroderma vasculopathy and ANCA (antineutrophil cytoplasmic antibodies)-associated glomerulonephritis have rarely been reported to occur simultaneously in one patient. Herein, we report a patient who presented with a classic constellation of clinical and laboratory findings of systemic scleroderma and was subsequently found to be positive for p-ANCA. Two renal biopsies, performed 5 months apart, demonstrated typical changes of the two entities in both acute and “healed” phases, which were analyzed by computer mapping techniques. The two renal biopsies were serially sectioned and stained routinely, and with CD31 and CD34 as endothelial markers. The slides were digitized, aligned and analyzed. Each glomerular tuft was sequentially studied in terms of total area (µm2) and each biopsy was individually profiled. All arterial vessels were sequentially studied with whole vessel and luminal areas delineated and ratios calculated. The initial biopsy contained 32 glomeruli almost all with extensive fibrinoid necrosis and destruction of the capillary network. The arterial vessels (interlobular and arcuate) showed intimal edema with luminal occlusion. CD31/CD34 stains showed variable endothelial intactness but demonstrated the luminal size shifts. The second biopsy had 37 glomeruli that were either segmentally or globally sclerotic with no active changes. The vessels were now normally patent. Each glomerular tuft and arterial vessel in both biopsies was analyzed as a serial section histogram documenting these changes. These studies depict the rare occurrence of two entities together, the scleroderma kidney vasculopathy and the glomerulonephritis of ANCA-associated vasculitis syndrome both in an acute and healing phase, profiled by computer mapping techniques